JP2011212918A - Metal slider - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slider which has good conductivity and shows a high wear-suppressing effect on both the slider and the partner material of the slider.SOLUTION: In the slider 1 composed of a laminate structure 1 in which copper-based layers 4 and steel layers 5 are alternately laminated on each other and the respective layers are bonded to each other by a metallic bond, the laminate structure 1 has, on the slide surface, a surface on which the copper-based layers 4 and the steel layers 5 are alternately exposed, wherein, on the slide surface, the slide direction 10 of the partner material of the slider is the alternately crossing direction through each layer, the number of the steel layers 5 is ≥3, the average thickness of the copper-based layers 4 in the slide direction is 0.01 to 0.20 mm, and a ratio R of the copper-based layers 4 to the steel layers 5 is 0.04 to 0.75.

Description

  The present invention relates to a "slider" using a composite metal material that slides with a sliding mating member such as a trolley wire, in which copper layers and steel layers are alternately laminated and joined. It is.

  In the case of supplying electric power to a moving object, a technique of bringing metal materials into sliding contact with each other is widely used. The current collectors of trains are the most commonly known, but in addition, sliding contact between metal materials is also used for traveling cranes in factories and yards, various moving objects in factories, motor brushes, and amusement park vehicles. There is something that uses.

  In sliding contact between metal materials, wear resistance characteristics of both materials are extremely important. In the case of a current application, conductivity is also important. In the case of a high-speed moving body such as a railway vehicle, the slider (slip plate attached to the pantograph) is made of a wear-resistant copper alloy, sintered material, carbon material, etc. (Slip plate) and sliding counterpart material (trolley wire) are suppressed from being worn. Although the conductivity of such a material is inferior to that of a general energizing material, a sufficient energizing current is ensured by increasing the voltage of the trolley wire (DC 600-1500 V, AC 20000-25000 V).

  However, there are many cases where it is not possible to increase the voltage of the sliding material for safety in factories and amusement park facilities. In addition, if a metal material for normal current-carrying parts is used for the slider, the wear of the slider or sliding material may increase even if the moving speed is relatively low, and the running cost of operating the equipment Increase factor.

JP 2009-096023 A

  It is an object of the present invention to provide a slider having good conductivity and having a high wear-suppressing effect on both the slider and the sliding counterpart material.

The above object is a slider composed of a laminated structure in which copper layers and steel layers are alternately laminated and each layer is metal-bonded. The laminated structure has copper layers and steel layers alternately. Hold the exposed surface on the sliding surface, and within the sliding surface,
Sliding direction of sliding mating material: direction crossing each layer alternately,
Number of steel layers: 3 layers or more,
Average thickness of the copper-based layer in the sliding direction: 0.01 to 0.20 mm,
Copper-based layer / steel layer ratio R: 0.04 to 0.75,
This is achieved by a metal slider that is The sliding partner material is, for example, a copper-based material. This slider is an energizing member that energizes, for example, by electrical contact with a sliding mating member.

  Here, “copper-based” means one made of copper or a copper alloy. As the copper alloy, those having a copper content of 70% by mass or more are suitable. "Metal bonding" means that metals are bonded without using an adhesive mainly composed of organic or inorganic non-metallic components. Specifically, electroplating, diffusion bonding, brazing, etc. Is mentioned.

  It is extremely efficient to apply a copper-plated steel sheet as a material for constructing the laminated structure. It is not always easy to obtain a sound joint (ie, with few joint defects) by directly joining a copper-based material and a steel material. For example, in the case of diffusion bonding, a copper material and a steel material cannot be directly diffusion-bonded unless a high surface pressure is applied and heated at a high temperature, so that industrial implementation at low cost is difficult. In addition, when steel sheets and copper-based sheets are alternately overlapped and the copper-based sheet itself is brazed and joined as a brazing material, the wettability of the steel and the copper-based molten metal (brazing material) becomes insufficient. Voids are likely to occur. On the other hand, when the copper plating layers of the copper plated steel plates are overlapped and the contact portions of the copper plating layers are diffusion bonded, diffusion bonding can be realized at a relatively low surface pressure and a relatively low temperature. Even when the copper plating layer is brazed and joined as a brazing material, both copper plating layers are likely to react with each other, and brazing is relatively easy. If the required copper-based layer thickness is not enough for the copper plating layer to cover, the copper-based metal sheet is sandwiched between the copper-plating layers, and diffusion bonding is performed at the contact points between the copper-based materials. Just do it.

  A slider attached to the structure via a spring mechanism so as to be movable in a direction perpendicular to the sliding surface can be suitably employed as the slider composed of the above laminated structure.

  According to the present invention, the wear of both the slider and the sliding counterpart material can be remarkably suppressed, and the slider is a metal material containing a copper-based metal, and therefore has high conductivity. In addition, since a general-purpose material that has already been mass-produced industrially can be manufactured as a raw material, the cost is lower than that of a special current collecting material such as a sintered alloy. The slider of the present invention has high utility value not only as a high-speed moving body but also as a current collecting member in a low-voltage, low-speed moving body.

The figure which illustrated typically the cross section of the metal sliding element of this invention, and the sliding other party material which slidably contacts with it. The figure which illustrated typically the cross section of the metal sliding element of this invention, and the sliding other party material which slidably contacts with it. A cross-sectional optical micrograph of a laminated structure obtained by diffusion bonding copper-plated steel sheets. FIG. 4 is a cross-sectional optical micrograph in which a partial region of FIG. 3 is enlarged.

  FIG. 1 schematically illustrates a cross section of the metal slider of the present invention and a sliding mating member in sliding contact therewith. The slider 1 is composed of a laminated structure in which copper layers 4 and steel layers 5 are alternately laminated and integrated by metal bonding. The slider 1 is in sliding contact with the sliding partner material 2 on the sliding surface 3. An arrow 10 indicates the sliding direction. Looking at the slider 1 as a reference, the sliding counterpart material 2 moves relative to the slider 1 in the sliding direction 10 (whichever direction of the arrow may be used). At that time, the sliding counterpart 2 slides so as to alternately cross the copper layers 4 and the steel layers 5 in the sliding surface 3. FIG. 1 illustrates the case where the layer interface 7 is perpendicular to the sliding surface 3.

  According to the inventors' research, the wear of both the metal slider 1 and the sliding counterpart 2 is caused by the sliding counterpart 2 rubbing the copper layer 4 and the steel layer 5 in the sliding surface 3 alternately. Can be remarkably suppressed. The mechanism is not fully understood at this time.

  If the number of the copper-based layers 4 and the steel layers 5 present in the sliding surface 3 is too small, the wear suppression effect may not be sufficiently exhibited. As a result of various studies, the present invention is directed to a case where three or more steel layers 5 exist in the sliding surface 3. That is, the sliding partner material 2 is in sliding contact with at least three steel layers 5 and at least two copper-based layers 4 in the sliding surface 3. In the example of FIG. 1, chamfers 6 are formed at both ends in the sliding direction of the slider 1, and the layer indicated by the symbol a or b in the drawing in the steel layer 5 has a thickness within the sliding surface 3. There is a part of the direction. Thus, the steel layer 5 in which only a part in the thickness direction of the layer exists in the sliding surface 3 is also counted as the steel layer 5 existing in the sliding surface 3. In the example of FIG. 1, the number of steel layers 5 present in the sliding surface 3 is 11 layers.

  If the thickness of the copper-based layer 4 in the sliding surface 3 is too thick, the copper-based metal of the copper-based layer 4 is peeled off and easily adheres to the sliding counterpart material 2. As a result of detailed studies by the inventors, reducing the average thickness in the sliding direction of the copper-based layer 4 in the sliding surface 3 to a certain extent or less makes the wear of both the slider 1 and the sliding counterpart material 2 remarkable. It was found that it is extremely important to suppress it. Specifically, it is effective that the average thickness of the copper-based layer 4 in the sliding direction is 0.20 mm. You may manage to 0.15 mm or less, or also 0.10 mm or less. However, if the thickness of the copper-based layer 4 is too thin, the presence effect is reduced, and the wear of the sliding counterpart material 2 is increased. Further, in energization applications, there may be a case where a decrease in conductivity becomes a problem. As a result of various studies, it is desirable to secure an average thickness in the sliding direction of the copper-based layer 4 of 0.01 mm or more.

  The sliding direction 10 does not necessarily need to be perpendicular to the layer interface in the sliding surface 3. When the sliding direction 10 is perpendicular to the layer interface, the average thickness of the copper-based layer 4 appearing in the sliding surface 3 matches the average thickness of the copper-based layer 4 in the sliding direction.

  If the abundance ratio of the copper-based layer 4 existing in the sliding surface 3 is excessive, the copper-based metal is applied to the sliding counterpart 2 even if the average thickness in the sliding direction of the copper-based layer 4 is within the specified range. The phenomenon of adhesion tends to occur. Moreover, since the abundance ratio of the steel layer 5 becomes small when the abundance ratio of the copper-based layer 4 increases, the strength may be insufficient depending on the application. As a result of the study, it is desirable that the copper layer / steel layer ratio R is 0.04 to 0.75 in the sliding surface 3. More preferably, it is 0.05 to 0.50. Here, the copper layer / steel layer ratio R is “the total thickness in the sliding direction of the copper layer 4 existing in the sliding surface 3” “the sliding of the steel layer 5 existing in the sliding surface 3”. It is divided by the “direction total thickness”.

  FIG. 2 schematically illustrates a cross-section of the metal slider of the present invention and a sliding mating member slidably contacting the same as in FIG. In this case, however, the layer interface 7 is not perpendicular to the sliding surface 3. Such a mode can be adopted when it is desired to adjust the thickness of the copper-based layer 4 or the steel layer 5 appearing on the sliding surface 3.

  Various steel types can be adopted as the steel layer 5. When a steel type that can harden the cross-sectional hardness of the steel layer 5 to 300 HV or higher, or even 400 HV or higher by tempering heat treatment such as quenching or austempering, both the slider 1 and the sliding counterpart 2 are used. The effect of suppressing wear and tear is improved. For example, S35C, S55C, SCM415, SCM435, SNCM420, SK85, SUJ2, and the like can be cited as examples of such steel types. In addition, since the copper-type layer 4 is not hardened | cured by tempering heat processing, the slider with which the steel layer 5 hardened | cured can be obtained by using a laminated structure for normal tempering heat processing as it is.

  The copper-based layer 4 is copper or a copper alloy. Various copper alloys can be considered as application targets. Typically, Cu-Zn alloys having a Zn content of 30% by mass or less can be cited. When using an electro-copper-plated steel sheet as a material, in order to make the copper-based layer 4 a copper alloy, metal bonding may be performed with a copper-based metal sheet having a predetermined composition and thickness interposed therebetween.

  As the copper-plated steel sheet, an electrolytic copper-plated steel sheet obtained by a general electrolytic copper plating method can be applied. The plate thickness of the steel plate that is the plating base plate is selected within a range that satisfies the specifications of the sliding direction average thickness of the copper-based layer and the copper-based layer / steel layer ratio R, and is generally generally 0. What is necessary is just to use the plating original plate of about 05-2.0 mm.

  The sliding partner material 2 is preferably a copper-based material. A typical example is a trolley wire.

  As a manufacturing method of the laminated structure, after overlapping a plurality of copper-plated steel sheets as described above, a method of brazing and bonding the copper plating layer itself as a brazing material, a method of diffusion bonding the copper plating layers, or For example, a diffusion bonding method in which a copper-based metal sheet is sandwiched between copper-plated steel sheets can be applied.

In the case of diffusion bonding, for example, the following method can be exemplified.
A laminated body in which a plurality of copper-plated steel plates are overlapped is placed in a vacuum furnace and evacuated to a reduced pressure atmosphere of 10 Pa or less. The pressure is more preferably 1 Pa or less, and still more preferably 0.5 Pa or less. The laminated body is maintained in a temperature range of 780 to 950 ° C. with a lamination direction pressure of 1.5 to 6.0 MPa applied. The stacking direction pressure is the average (average surface pressure) of the surface pressure applied between the copper plating layers. According to the inventors' investigation, diffusion bonding between copper plating layers has a feature that a sound diffusion bonding portion can be obtained at a relatively low surface pressure and low temperature. In order to take advantage of this feature, it is preferable to carry out at a relatively low lamination direction pressure of, for example, 4.0 MPa or less, or 3.0 MPa or less.

  When the heating temperature is lower than 780 ° C., it is necessary to apply a relatively high stacking direction pressure and hold it for a long time. More preferably, the temperature is 790 ° C or higher. On the other hand, high-temperature heating exceeding 950 ° C. causes an increase in cost, and the merit of using a copper-plated steel sheet cannot be utilized. More preferably, the heating temperature is 900 ° C. or lower, and the temperature can be controlled to 840 ° C. or lower. The time for maintaining the temperature can be shortened as the surface pressure and temperature increase. What is necessary is just to set an appropriate holding time in the range of 30-300 min, for example according to the lamination direction pressure and heating temperature to provide. The appropriate holding time can be set based on preliminary experiment data. After completion of heating and holding for a predetermined time, it is preferable to cool in a furnace in which outside air is shut off until the material temperature becomes 200 ° C. or lower. When steel with good hardenability is used as the plating base plate, it is possible to perform the quenching process by utilizing the cooling after the heating and holding of the diffusion process.

  For reference, FIG. 3 shows a cross-sectional photograph of a laminated structure obtained by diffusion bonding copper plated steel sheets at 800 ° C. The gray part is the steel layer and the white line is the copper layer. FIG. 4 shows an enlarged cross-sectional photograph of a part of FIG. The trace of the interface between the copper plating layers cannot be confirmed.

  Thus, the laminated structure in which the layers are integrated by metal bonding is subjected to a tempering heat treatment as necessary, and then processed into a slider having a predetermined shape. When the slider is attached to a structure (such as a vehicle), it is attached to the structure via a spring mechanism so as to be movable in a direction perpendicular to the sliding surface 3 (arrow 20 in FIGS. 1 and 2). Can do. A typical example of the spring mechanism is a pantograph, but it may be directly attached to the structure via a coil spring, an air spring, or the like.

The following materials were prepared as materials for producing the laminated structure.
[Electro copper plated steel sheet]
・ Plating base plate;
Steel type: S55C, SCM415 (both JIS standard equivalent materials)
Thickness 0.25mm, 1.0mm
-Copper plating layer;
Composition: Pure copper Thickness: 2.5 μm per side, 10 μm, equal thickness on both sides [copper sheet]
Pure copper plate with thickness of 0.25mm and 0.06mm

  A method of superposing a plurality of the same type of copper electroplated steel sheets and brazing the copper plating layer itself as a brazing material, a method of superposing a plurality of the same type of electro copper plated steel sheets and performing diffusion bonding, or A laminated structure was produced by a method in which copper sheets were alternately stacked and diffusion bonded. Diffusion bonding was performed by heating to 900 ° C. with a surface pressure of 1.5 MPa applied under a reduced pressure of 10 Pa or less. Brazing joining was performed by heating at 1150 ° C. in an argon gas atmosphere of 1 atm. About some laminated structures, the austemper process was performed and the steel layer was hardened.

A test piece was cut out from each laminated structure, and hardness measurement, conductivity measurement, and sliding test were performed as follows.
[Hardness measurement]
The cross section hardness of the copper-based layer and the steel layer of the laminated structure was measured with a micro Vickers hardness meter.
[Conductivity measurement]
Using a test piece having a thickness of 5 mm, a width of 10 mm, and a length of 120 mm, conductivity was measured according to JIS H0505. However, one direction parallel to the layer interface of each layer was defined as a length direction, a direction parallel to the layer interface in a plane perpendicular to the length direction was defined as a thickness direction, and a direction perpendicular to the layer interface was defined as a width direction.

[Sliding test]
A slider having a sliding surface perpendicular to the layer interface was cut out from the laminated structure and brought into sliding contact with a rotating ring-shaped sliding mating member. The dimension of the sliding surface is approximately 16 mm parallel to the layer interface and approximately 12 mm perpendicular. The sliding partner material is a ring cut from a cold rolled material (100 HV) of a pure copper plate. The ring dimensions are an outer radius of 115 mm, an inner radius of 105 mm, a ring width of 5 mm, and a ring height of 10 mm. The sliding direction was a direction that crossed each layer in the sliding surface substantially at a right angle.

  In the test, sliding for 1 min was repeated 8 times under the conditions of non-lubricated, normal temperature atmosphere, load 30 N, and ring rotation speed 1200 rpm. The specific wear amount of the slider and the wear amount of the sliding counterpart material after the sliding test were measured.

As a comparative slider, S55C bulk material and iron-based sintered material (Fe-2% Ni-2% Ti-1% W-3%) used as a pantograph sliding plate material for high-speed railway vehicles Mo-10% Pb) was prepared, and the same test as above was performed.
The results are shown in Table 1.

As can be seen from Table 1, in the example of the present invention, the wear of both the slider and the sliding partner material was small, and the conductivity was also good.
On the other hand, Comparative Example No. 1 has a small average thickness in the sliding direction of the copper-based layer and a small copper-based layer / steel layer ratio R, so that the wear of the sliding counterpart material is large and the conductivity is poor. It was. No. 5 has a large average thickness in the sliding direction of the copper-based layer and a large copper-based layer / steel layer ratio R, so the wear of the slider is large, and the copper from the copper-based layer is the sliding counterpart material. Attached. In No. 6, the average thickness in the sliding direction of the copper-based layer was within an appropriate range, but since the copper-based layer / steel layer ratio R was small, the wear of the sliding counterpart material was large and the conductivity was also poor. Since No. 7 is a bulk steel material, both the slider and the sliding mating material were greatly worn and inferior in conductivity. No. 8 achieves good current collection in a high-speed railway vehicle, but under such relatively low-speed sliding conditions, both the slider and the sliding counterpart material are greatly worn and the conductivity is low. .

1 Slider (laminated structure)
2 Sliding partner 3 Sliding surface 4 Copper layer 5 Steel layer 6 Chamfer 7 Layer interface 10 Sliding direction 20 Vertical direction to sliding surface

Claims (7)

A slider comprising a laminated structure in which copper-based layers and steel layers are alternately laminated and each layer is metal-bonded. Hold on the sliding surface and within the sliding surface,
Sliding direction of sliding mating material: direction crossing each layer alternately,
Number of steel layers: 3 layers or more,
Average thickness of the copper-based layer in the sliding direction: 0.01 to 0.20 mm,
Copper-based layer / steel layer ratio R: 0.04 to 0.75,
Is a metal slider.   The metal slider according to claim 1, wherein the sliding partner material is a copper-based material.   3. The metal slider according to claim 1, wherein the laminated structure is obtained by superposing a plurality of copper-plated steel plates and diffusion bonding the contact portions between the copper-plated layers.   3. The metal slider according to claim 1, wherein the laminated structure is obtained by superposing a plurality of copper-plated steel plates and brazing each copper plating layer as a brazing material.   3. The metal sliding according to claim 1, wherein the laminated structure is obtained by alternately superimposing copper-plated steel plates and copper-based metal sheets and diffusion bonding the contact portions of the copper-plated layers and the copper-based metal sheet. Child.   The metal slider according to claim 1, wherein the slider is attached to the structure via a spring mechanism so as to be movable in a direction perpendicular to the sliding surface.   The metal slider according to any one of claims 1 to 6, wherein the slider is a current-carrying member that conducts electricity by electrical contact with a sliding partner material.